Self-inverting water-in-oil emulsions of water-soluble polymers

摘要

A water-in-oil emulsion of a water-soluble polymer such as acrylamide/acrylic acid copolymer having improved invertibility is prepared by (1) adding a portion of an inverting surfactant such as sorbitan trioleate having 20 polyoxyethylene units to a water-in-oil emulsion of water-soluble monomer, (2) polymerizing the monomer and (3) adding a remaining amount of inverting surfactant to the emulsion.